textproduct: Quad Cities

KEY MESSAGES

- Ongoing Winter Weather Advisory for generally 2 to 4 inches has been expanded east and south for late tonight and Saturday.

- Very cold/arctic air moving in for the weekend. Biting wind chills well below zero late tonight, and especially Saturday night into Sunday morning where wind chills of -20 to -30 are likely.

- Warming trend still on track for mid next week.

SHORT TERM /THROUGH SATURDAY/

Issued at 251 PM CST Fri Dec 12 2025

Upper low currently acrs the Manitoba/Ontario border will look to dig and deepen into the northern GRT LKS through Saturday evening. This process will sweep the first cold front and initial lobe of Canadian high pressure through the area tonight with veering and increasing northwesterly sfc winds, and then the main arctic surge coming Saturday night with in-crashing 1040+ MB arctic high. For this early evening, initial short wave and pre-frontal forcing may wring out flurries or even spotty light freezing drizzle out of any low stratocu deck especially north of I-80. Then a late evening and overnight lull as northwesterly post-frontal northwest sfc winds increase and cold air advect. Then all eyes focus on the now well advertised in-coming clipper in tightening northwest steering flow aloft and northwest-to-southeast oriented LLVL baroclinicity. More top-down saturation to do with initial incoming lift and may delay the snow at ground level start time some, but for now have kept the headline timing the same. But with new precip/snow calculations and neighboring office collaboration, have expanded the winter wx advisory east and south.

Snow Amounts: Looking at the fcst soundings and vertical profile ensembles, they still advertise deep saturation by Sat morning, with over 150 MB LLVL saturation in the dendritic layer. Extent of upward omegas, F-gen and adequate RH in the cold profiles still pointing to a proficient snow maker with heavy rates of 1-2 inches an hour for a period of 2-4 hours, making the most of a QPF of 0.10 to 0.25 of an inch of liquid possible, doubling those QPF amounts in snowfall(2 to 5+) inches in the higher snowfall swath. Looks like a bit broader and further north heavier snow axis from the one that occurred last night, with the highest amounts from I-80 south to the Hwy 34 corridor. Or along a Sigourney IA, to Burlington, and south of Monmouth IL line. Most of the snow to fall from 6 AM to noon, with tapering windows on either side. Most snow out of the area by 4 PM Sat.

Temperatures: The cold air advection and northern plains/south central Canada source region support low temps well down in the single digits, with even some sub-zero readings possible in the north. The northwest winds will make for Saturday morning wind chills from 10 to near 20 below zero for much of the area and thus an added threat for somebody having car trouble Sat morning for those who need to travel. With the clouds and snow, high temps may struggle to get out of the single digits especially north of I-80.

LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/

Issued at 251 PM CST Fri Dec 12 2025

Saturday night and Sunday...the brunt of the arctic ridge pummels it's way down acrs the region, with -20C H85 MB temp cold pool glancing the CWA. But with the ongoing stout CAA and snow pack, northwest sfc winds of 15 to 20 MPH into Sunday morning to bring about low temps of -5 in the south, to near -15F in the northwest. Of course the big thing will be the advecting winds themselves of 10- 20 MPH combining with the very cold ambient temps to produce widespread wind chills of 20 below to 30 below zero. Have collaborated with other offices to get the headline out a bit early and thus a cold advisory has been hoisted for Saturday night through midday Sunday. Additional shifts will have to assess the possible need of and upgrade to a warning if need be, especially acrs the northwest third of the DVN CWA. Sunday highs in the low to mid single digits above zero could be a bit optimistic. Temps to crash fast with decreasing winds by Sunday evening nightfall, leading to another sub zero 3 dog night.

We may need another cold headline north of I-80 for Monday morning, with wind chills of 20 below or a few degrees colder.

Longer range progs and ensembles still show flattening steering flow acrs the mid CONUS into mid next week, and thus a moderating temp regime into mid next week. Snow melt and fog may be a factor through Wednesday, before a progressive stronger low pressure system sweeps through the region with rain chances Wed night into Thu, before a post-system chill down occurs into the end of next week.&&

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1159 AM CST Fri Dec 12 2025

Challenging CIG height and VSBY fcst this afternoon with varying VFR to IFR CIGs and lighter fog. It should trend to mainly MVFR for both parameters as the afternoon and early evening progresses. Until then, will have to watch for a few flurries or spotty freezing drizzle at DBQ through mid afternoon. Then an incoming arctic front will veer the winds to the northwest with an increase to 10-20 KTs mid to late evening scooping up CIGs and mixing out any lingering fog into the overnight. Then here comes the next clipper system with light to moderate snow moving in from the west-northwest by dawn...first to hit CID around 10-11z or so. There will be a rapid deterioration in both CIGs and snow reduced VSBYs at all sites through mid morning back to IFR or LIFR except maybe at DBQ which may hold on to low MVFR criteria through 18z.

DVN WATCHES/WARNINGS/ADVISORIES

IA...Cold Weather Advisory from 6 PM Saturday to noon CST Sunday for IAZ040>042-051>054-063>068-076>078-087>089-098-099. Winter Weather Advisory from 3 AM to 3 PM CST Saturday for IAZ063-064-076-077-087-088-098-099. Winter Weather Advisory from 6 AM to 6 PM CST Saturday for IAZ065-067-068-078-089. IL...Cold Weather Advisory from 6 PM Saturday to noon CST Sunday for ILZ001-002-007-009-015>018-024>026-034-035. Winter Weather Advisory from 6 AM to 6 PM CST Saturday for ILZ015>018-024>026-034-035. MO...Cold Weather Advisory from 6 PM Saturday to noon CST Sunday for MOZ009-010. Winter Weather Advisory from 3 AM to 3 PM CST Saturday for MOZ009-010.